This invention relates to a system for producing and storing sodium hypochlorite for use as a sanitizing solution.
There is a constant need for the production of sanitizing chemicals for both industry and home use. Dairies, food processing plants, bottling plants and swimming pools all require large volumes of chlorine, which is usually supplied as an aqueous hypochlorite solution. Sodium hypochlorite is the most prevalent of these chemicals and is made by reacting sodium hydroxide with chloride in an aqueous environment according to the following equation: EQU 2 NaOH+Cl.sub.2 .fwdarw.NaOCl+NaCl+H.sub.2 O
The generation of chlorine and sodium hydroxide is usually carried out in large commercial electrolytic cells and the resulting aqueous sodium hypochlorite is bottled or processed for bulk shipment. This is expensive as large amounts of water must be transported and the solution is caustic and dangerous to handle.
One method of on-site generation of chlorine to lessen this problem is taught in U.S. Pat. No. 3,819,329 issued June 25, 1974. In this patent, a saturated saline solution and fresh tap water are admixed prior to introduction into electrolytic cells. Separate introduction is not needed because the anode and cathode compartments in the cells are not separated. Instead, the reactants enter a common cell and products exit intermixed. The resulting products are hypochlorous acid, sodium hypochlorite, hydrochloric acid and other by-products. Because of the addition of acetic acid to the brine solution prior to its introduction into the cell, the saturated salt solution enters the cell with a pH of 6.0. By lowering the pH, the product solution constitutes primarily hypochlorous acid, a relatively unstable compound. Its inherent instability requires its immediate use by means of the spray system set forth in the patent. The objective of the patent was to eliminate the need for storage and preservation and instead produce an unstable hypochlorous acid. However, in many instances, it is both desirable and preferable to produce and use a more stable chlorine compound which is capable of storage. The system of the present invention will eliminate many time-consuming steps as well as the need to use immediately that chlorine which is produced.